Refrigerating apparatus

ABSTRACT

This invention relates to a refrigerating apparatus. Said apparatus comprises a compressor of the oil injection system, a condenser containing a liquid refrigerant, a line connecting an outlet port of said compressor to said condenser, an evaporator, a line connecting an upper portion of a liquid sump in said condenser to said evaporator, a line connecting said evaporator to a suction port of said compressor, an oil sump formed in a bottom portion of said condenser, and a line connecting said oil sump to an oil injection port of said compressor. Said refrigerant in a high pressure gaseous state from said compressor is injected together with oil into said liquid refrigerant so as to effect condensation of the refrigerant gas, separation of the refrigerant from the oil and cooling of the oil in said condenser.

United States Patent [191 Kasahara 1. REFRIGERATING APPARATUS v[75] lnventorz Keisuko Kasahara, Tokyo, Japan [73] Assignee: Kabushiki Kaisha Maekawa Seisakusho, Tokyo, Japan [22] Filed: Jan. 26, 1973 [21] Appl. No.: 327,102

[30] Foreign Application Priority Data Feb. 21, 1972 Japan 47-17822 [52] V 11.8. CI 62/473, 62/84, 62/470 [51] Int. Cl. F251) 43/02 [58] Field of Search 62/84, 470, 473, 192

[56] References Cited UNITED STATES PATENTS 1,620,713 3/1927 Bell 62/473 1,834,136 1/1931 Andrews 62/473 1,835,081 12/1931 Pollard 62/473 2,618,132 11/1952 Pottenger 62/192 3,201,949 8/1965 Kocher 62/473 3,274,796 9/1966 Kocher 62/473 3,534,564 10/1970 Miller 62/84 [451 July 9, 1974.

Primary Examiner-William J. Wye Attorney, Agent, or FirmStevens, Davis, Miller & Mosher [57] ABSTRACT This invention relates to a refrigerating apparatus.

Said apparatus comprises a compressor of the oil injection system, a condenser containing a liquid refrigerant, a line connecting an outlet port of said compressor to said condenser, an evaporator, a line connecting an upper portion of a liquid sump in said condenser to said evaporator, 21 line connecting said evaporator to a suction port of said compressor, an oil sump formed in a bottom portion of said condenser,

, and a line connecting said oil sump to an oil injection port of said compressor.

Said refrigerant in a high pressure gaseous state from said compressor is injected together with oil into said liquid refrigerant so as to effect condensation of the refrigerant gas, separation of the refrigerant from the oil and cooling of the oil in said condenser.

5 Claims, 4 Drawing Figures PATENTEU JUL 91974 i 3 822 567 sum 1 0F 2 I PATENTEUJUL w 3.822.567

PRIOR ART,

1 REFRIGERATING APPARATUS.

This invention relates to refrigerating apparatus comprising a compressor of the oil injection system, and more particularly it is concerned with a refrigerating apparatus of the type described in which condensation of a refrigerant, separation of oil from the refrigerant and cooling of the oil take place in the. condenser.

Conventional refrigerating apparatus of the oil injection system are constructed such that, in the refrigeration cycle, a suitable refrigerant gas is compressed in a compressor and discharged therefrom in a gaseous state together with oil, the oil is separated from the refrigerant in a gaseous state by means of an oil separator, the gas is passed through a condenser where it gives off heat and changes into a liquid state, the liquid is stored in a liquid sump from which it is passed through an evaporator to absorb heat and change the refrigerant back to a gaseous state for compressing in the compressor to complete the refrigeration cycle. The oil separated from the refrigerant in a gaseous state by means of the oil separator is cooled by an oil cooler before being returned to and injected into the compressor.

lnconventional refrigerating apparatus of the oil injection system, the oil separaton oil cooler and liquid sump are independent parts, so that the apparatus have the disadvantage of being large in overall size and complex in construction.

Accordingly, an object of the invention is to provide a refrigerating apparatus of the oil injection system which obviates the aforementioned disadvantages of the prior art by eliminating the oil separator, oil cooler and liquid sump.

Another object of the invention is to provide a refrigerating apparatus of the oil injection system wherein a refrigerant in a liquid state is stored in the condenser and the refrigerant gas under high pressure from the compressor is injected together with oil into the refrigerant in a liquid state in the condenser whereby condensation of the refrigerant gas, separation of the oil from the refrigerant gas and cooling of the oil can be effected in the condenser.

Additional and other objects of the invention as well as features and advantages of the invention will become evident from the description set forth hereinafter when considered in conjunction with the accompanying drawings, in which:

FIG. 1 is a vertical sectional side view of the condenser of the refrigerating apparatus according to this invention;

FIG. 2 is a vertical sectional front view of the condenser of the refrigerating apparatus according to the invention;

FIG. 3 is a flow diagram of the refrigerating apparatus according to the invention; and Y FIG. 4 is a flow diagram of a conventional refrigerating apparatus.

A condenser 4 shown in FIG. 3 is connected to one end of a higher pressure gas line 3 which is connected at the other end to an outlet port 2 of a compressor 1 -of the oil injection system.

Also in FIG. 3, a liquid line 6 connected at one end to an upper portion of a liquid sump 5 is connected at the other end to an evaporator 8 throughan expansion valve7, and a lower pressure gas line 9 connected at one end to the evaporator 8 is connected at the other end to a suction port 10 of the compressor 1. A cooling water line 11 of the shell and tube type is inserted in an upper portion of the condenser 4.

The one end of the higher pressure gas line 3 is maintained in communication with gas injection pipes 12 immersed in the liquid in the liquid sump 5 and each formed therein with a large number of small gas injection openings 13 disposed in spaced apart relationship as shown in FIG. 1 and FIG. 2. Wire mesh demisting plates 14 and 15 are mounted above and below the gas injection pipes 12. An oil sump 17 having an upper opening covered with a porous plate 16 projects downwardly from the bottom of the condenser 4 and connected to one end of an oil line 18 which is connected at the other end to an oil injection'port 19 of the compressor 1.

In operation, higher pressure gas ejected through the outlet port 2 of the compressor 1 is introduced together with oil through the higher pressure gas line 3 into the gas injection pipes 12 in the liquid sump 5 of the condenser 4, and injected through the small openings 13 into the refrigerant in a liquid state in the liquid sump 5. At this time, the higher pressure gas which is maintained at about C in the higher pressure gas line 3 is injected'into the liquid at about 35C and scattered therein, so that oil in the gas is cooled by the liquid and at the same time moves downwardly and separates itself from the refrigerant in a liquid state due to the difference in specific gravity, so that. the oil is sedimented below the liquid.

The interior of the condenser 4 is cooled by cooling water of about 20C circulating through the water line 11, so that the gas which remains in un-condensed state is cooled and condensed into a liquid by the water line 11 disposed above theliquid. Moreover, the plates 14 and 15 mounted above and below the gas injection pipes 12 are thoroughly cooled in the liquid, so that the oil in the injected gas is caught by the plates 14 and 15 and moves downwardly in droplets from the plates 14 and 15 without being incorporated in the liquid. The lower plate 15 further performs the function of preventing disturbance of the oil-liquid interface by preventing agitation of the lower portion of the liquid which might otherwise be caused by the injection of gas.

The refrigerant in a liquid state in the liquid sump 5 is supplied through the liquid line 6 from the upper portion of the sump 5 to the evaporator 8 where the refrigerant is changed back into a gaseous state and passed to the suction port 10 of the compressor 1. The oil in the oil sump 17 is supplied through the oil line 18 to the oil injection port 19 of the compressor 1. The oil may be supplied to the compressor 1 by the differential pressure between the condenser 4 and compressor 1 or by means of an oil pump mounted in the oilline 18.

From the foregoing description, it will be appreciated that the refrigerating apparatus according to the invention is constructed and operated such that the liquid stays in'the condenser and higher pressure gas is in- 6O jected together with oil from the compressor into the liquid for effecting condensation of the refrigerant and separation of the refrigerant from the oil and cooling of the oil in the single condenser. The apparatus according to the invention is more simple in construction and operation than the conventional refrigerating apparatus shown in FIG. 4 in which an oil separator 20, oil,

cooler 21 and higher pressure liquid sump 22 are mounted separately because these devices as well as 3 lines connecting them together can be done without and the condenser has only to be controlled. The elimination ofoil cooler ofiers the additional advantage of the loss of pressure injected into the compressor being reduced.

What is claimed is:

l. A refrigerating apparatus comprising a compressor of the oil injection system, a condenser containing a liquid refrigerant, a line connecting an outlet port of said compressor to said condenser, an evaporator, a line connecting an upper portion of a liquid sump in said condenser to. said evaporator, a lineconnecting said evaporator to a suction port of said compressor, an oil sump formed in a bottom portion of said condenser, a line connecting said oil sump to an oil injection port of said compressor, and means to inject said refrigerant in a high pressure gaseous state from said compressor together with oil into said liquid refrigerant so as to effect condensation of the refrigerant gas, separation of the refrigerant from the oil and cooling of the oil in said condenser.

2. A refrigerating apparatus as set forth in claim 1 wherein said means to inject comprises at least one gas injection pipe immersed in the liquid in said liquid sump and connected to the outlet port of said compressor through said line, said gas injection pipe being formed therein with a number of small gas injection openings.

3. A refrigerating apparatus as set forth in claim 2 further comprising at least one wire mesh demisting plate disposed above said gas injection pipe.

4. A refrigerating apparatus as set forth in claim 2 further comprising at least one wire mesh demisting plate disposed below said gas injection pipe.

5. A refrigerating apparatus as set forth in claim 2 further comprising a plurality of wire mesh demisting plates disposed above and below said gas injection pipe. 

1. A refrigerating apparatus comprising a compressor of the oil injection system, a condenser containing a liquid refrigerant, a line connecting an outlet port of said compressor to said condenser, an evaporator, a line connecting an upper portion of a liquid sump in said condenser to said evaporator, a line connecting said evaporator to a suction port of said compressor, an oil sump formed in a bottom portion of said condenser, a line connecting said oil sump to an oil injection port of said compressor, and means to inject said refrigerant in a high pressure gaseous state from said compressor together with oil into said liquid refrigerant so as to effect condensation of the refrigerant gas, separation of the refrigerant from the oil and cooling of the oil in said condenser.
 2. A refrigerating apparatus as set forth in claim 1 wherein said means to inject comprises at least one gas injection pipe immersed in the liquid in said liquid sump and connected to the outlet port of said compressor through said line, said gas injection pipe being formed therein with a number of small gas injection openings.
 3. A refrigerating apparatus as set forth in claim 2 further comprising at least one wire mesh demisting plate disposed above said gas injection pipe.
 4. A refrigerating apparatus as set forth in claim 2 further comprising at least one wire mesh demisting plate disposed below said gas injection pipe.
 5. A refrigerating apparatus as set forth in claim 2 further comprising a plurality of wire mesh demisting plates disposed above and below said gas injection pipe. 